About
Charcot foot also known as Neuropathic arthropathy or neuropathic osteoarthropathy refers to progressive destruction of joints of the foot, the process is marked by bony destruction, bone resorption, and eventual deformity due to loss of sensation & joint position sense. Any pathology that leads to loss of sensation in a joint may lead to a Charcot joint most common cause is diabetic neuropathy. The pathological process can gradually result in joint deformity, ulceration, loss of function. Early identification of joint changes is the best way to limit morbidity/ retard bone destruction.
Depending on the anatomical site of involvement Charcot’s foot can be classified into midfoot & hindfoot arthropathy.
Symptoms
Presentation is variable, depending upon the stage of the disease. Pain, swelling, redness with deformity of the foot, loss of grip on weight-bearing and instability of the foot. Altered loading of the deformed foot can result in pressure sores at the sole.
Investigations
Investigations will ascertain the cause of Charcot’s neuropathy. HBA1C testing is required to assess diabetic control while ESR & CRP to rule out infections &. Weight-bearing plain X-rays would evaluate the amount of bone destruction and determine the extent of the deformity of the forefoot, midfoot and hindfoot. MRI scans are necessary in double full cases of infections without bone destruction.
Management
The primary goal of treatment is to stabilize the foot and ankle so that patients can walk comfortably without pain and also prevent recurrent ulcerations. Management of Charcot’s foot varies upon the stage of the disease process, location of pathology, and the presence of ulcer and infection.
In the initial stages of the disease, total contact casting is advised. In case of progression of deformity, surgical joint fusion of joints with correction of the foot deformity is performed.
Surgical
Surgical management involves resection of nonviable bone with correction of the deformity followed by fusion of involved joints with or without bone grafting from the iliac crest. Method of stabilization for midfoot Charcot’s includes using long screws to align the forefoot to the hindfoot (Medial & Lateral Column fusion) while maintaining the arch. For hindfoot Charcot’s stabilization intramedullary nails are used to align the heel, hindfoot & ankle with the leg bone- tibia(TibioTaloCalcaneal fusion).
Following surgery foot will be immobilized with below-knee plaster cast for six weeks and gradually allowed to weight-bearing after 3 months.
Midfoot Charcot’s
Figure 1: Preoperative x-ray showing destruction of the midfoot, splaying of the forefoot, with loss of the foot arch and collapse of the midfoot region.
Medial & Lateral Column fusion
Figure 2: Post-operative x-ray showing the correction of the deformity, with recreation of the arch of the foot, this negates the formation of the ulcers in the foot.
Tibiotalocalcaneal fusion
Figure 3: Clinical pictures showing the comparison of hindfoot deformity before and after surgery(Top row). Preoperative x-ray of the destruction of the hindfoot bones, out-ward deviation and deformity. Post-operative x-ray correction of deformity with nail insitu(bottom row).